1. Field of the Invention
The present invention relates, in general, to a microwave cooking apparatus. In particular, it relates to a microwave cooking apparatus equipped with a magnetron such that the height of a waveguide can be made low.
2. Description of the Related Art
In general, in a microwave cooking apparatus, the mounting construction of the waveguide and magnetron is as described in U.S. Pat. No. 4,162,380. Specifically, Burke, in U.S. Pat. No. 4,162,380, shows a waveguide that is formed by drawing a thin sheet. The waveguide is fixed by welding or caulking to the upper surface of a ceiling plate of an oven frame that is partitioned into a cooking chamber and a machine chamber. A magnetron, extending so as to project into the machine chamber, is fixed to the bottom surface of a mounting part of the ceiling plate, with its antenna projecting into the waveguide.
However, if the magnetron is mounted as described above, a suitable gap must be added to the height of the antenna of the magnetron in order to determine the height of the waveguide. Therefore, this presents an obstacle to lowering the external height of the casing of the microwave cooking apparatus, since the lower limit of the height of the waveguide is determined by the height of the antenna.